Ft. Pitt Bridge is not all that tight. You just need to slow to get around some of the turns. Not to mention that there could be people coming from the other direction.
And oh if you cross the Ft. Duquense Bridge from Pittsburgh to North Side, just be careful as you may have a rude awakening as you roll down the stairs at the other side.
And I would suggest that visitors cross over to the North Side. First there is the ballpark, the Mexican War streets with their beautiful homes and most important is Bicycle Heaven. A bicycle museum that has to be seen to be believed.